Background and aim of the study: The Mosaic bioprosthesis is a stented porcine aortic valve, which combines glutaraldehyde fixation with zero-pressure and root-pressure techniques and anti-mineralization treatment with amino-oleic acid for improved hemodynamics and tissue durability. The study aim was to collect intermediate-term data of the Mosaic bioprosthesis in the aortic position, the first device having been implanted in February 1994 at the authors' institution.
Methods: A total of 100 patients (49 females, 51 males) underwent aortic valve replacement with the Mosaic bioprosthesis between February 1994 and May 1999. Mean age at implant was 73.4 +/- 7.3 years. Concomitant procedures were performed in 40.0% of cases. Patients were followed up within 30 days postoperatively, after six months, and at annual intervals thereafter. Mean follow up was 3.8 years (range: 0.1-7.1 years); total follow up was 383.1 patient-years (pt-yr) and 100% complete.
Results: Early mortality (< or = 30 days) was 3.0%; late mortality was 4.6%/pt-yr, including a valve-related mortality of 0.6%/pt-yr. Freedom from event at seven years was 96.8 +/- 1.8% for thromboembolic events, 97.2 +/- 2.0% for thrombosed bioprosthesis, 96.6 +/- 2.6% for structural valve deterioration, 98.2 +/- 1.8% for nonstructural dysfunction, 95.9 +/- 2.0% for anti-thromboembolic hemorrhage, 98.9 +/- 1.1% for endocarditis, and 93.9 +/- 3.2% for reoperation/explant. After one year, the mean systolic pressure gradient was 15.3 +/- 6.7, 14.5 +/- 5.7, 12.7 +/- 4.1 and 12.9 +/- 4.8 mmHg for 21, 23, 25 and 27 mm valves respectively; the effective orifice area (EOA) was 1.4 +/- 0.4, 1.7 +/- 0.4, 1.8 +/- 0.4 and 2.6 +/- 0.4 cm2 for 21, 23, 25 and 27 mm valves respectively; and the EOA index was 0.8 +/- 0.3, 0.9 +/- 0.2, 0.9 +/- 0.2 and 1.3 +/- 0.1 cm2/m2 respectively. The mean left ventricular mass index was decreased significantly, from 159.7 +/- 56.8 g/m2 to 137.3 +/- 40.8 g/m2, for all valve sizes after one year.
Conclusion: Clinical and hemodynamic performance of the Mosaic bioprosthesis was highly satisfactory during the first seven years after clinical introduction.